The present invention relates to an improved method and kit for detecting explosives selected from nitroaromatics, organic nitrates (sometimes termed colloquially "nitroesters"), nitramines, inorganic nitrates, chlorates and bromates.
Particularly since what has become known as the Lockerbie incident, in which the undetected presence of explosive in an airplane resulted in tragic loss of life as well as material damage, an awareness of the need for rapid and reliable detection of explosives has become apparent. It is also evident that antiterrorist activity, more generally, will similarly make highly desirable, the availability of means for the ready detection of explosives. The present invention seeks to meet such needs, which are felt to an increasing extent at the present time.
An explosives detection kit marketed with the participation of the present assignees has proved highly successful commercially; see Almog. J. et al, J. Energetic Materials, 4: 159-167 (1986), who described a kit for detecting nitroaromatic, nitrate ester and nitramine explosives, the identification of inorganic nitrates being a later addition.
A "Field Spot-Test Kit for Explosives" using chemical reagents in a non-sequential procedure, as well as a portable ultraviolet lamp, has also been described (see Bayton, J. F., Los Alamos National Laboratory, New Mexico, USA, July 1991, NTIS publication # LA-12071-MS DE91 015321). However, this publication gives little or no indication of the sensitivity of the tests described therein. The disclosures of the above-stated literature articles are explicitly incorporated by reference herein.
In spite of the commercial success of a kit for detecting nitroaromatic, nitrate ester and nitramine explosives, based on the Almog et al model (above), this suffers from a number of drawbacks, which the present invention seeks to overcome, which drawbacks may be summarized as follows:
(1) two of the reagents are highly unstable to air and light, so that once the sealed ampoules containing them have been broken for test purposes, the kit has no reliable utility after 24 hours, and it is therefore discarded;
(2) one of the reagents is used in solid form, which, because of less reliable contact than a liquid, with a sample, makes a test utilizing it less reliable than is desirable;
(3) the existing kit does not detect chlorates, which are a possible ingredient of improvised explosives.